It has been discovered that the vibrissaeless rat blisters because of a suprabasilar adhesion defect, that the exfoliative mouse suffers a transient purulent conjunctivitis, exfoliates and may die. Survivors continue to have intermittant hair loss; masked rats have blepharitis accompanied by alopecia. Pasteurella organisms appear to be playing a role. The motheaten mouse has been found to have a hyperimmunoglobulinemia and usually dies of an autoimmune disease. Germfree environment has no effect on prolonging survival. An attempt has been made to classify and summarize genodermatoses involving neoplasia. BIBLIOGRAPHIC REFERENCES: Kent, R.L., Lutzner, M.A. and Hansen, C.T.: Masked rat: An x-ray induced mutant with chronic blepharitis, alopecia and pasteurellosis. J. Heredity, 67:3-5, 1976. Lutzner, M.A.: Monograph: The Genetics of Human Cancer. Edited by J.J. Mulvihill, R.W. Miller, and J.F. Fraumeni, Jr., National Cancer Institute. Nosology among the neoplastic genodermatoses, Vol. 3, pp. 145-167, 1977.